Fabric softening compositions are well known. Such compositions typically comprise a cationic or nonionic softening agent dispersed in water. When the level of softening agent is present in an amount up to 8% by weight, the compositions are considered dilute, and at levels from 8% to 60%, the compositions are considered concentrated. Usually, such conditioners are termed “rinse-added” since they are added into the wash during the rinse cycle.
It is known that concentrated fabric softening compositions can suffer from instability on storage. This can manifest itself as an irreversible thickening of the composition to the point where the composition gels and is no longer pourable.
To address this, nonionic alkoxylated alcohols can be provided in fabric softening compositions as a viscosity stabiliser for the composition. Such compounds are referred to herein as “nonionic stabilisers”.
However, the presence of nonionic stabilisers can adversely affect softening performance, and the greater the amount of nonionic stabiliser present, the more adverse the effect on the softening performance can be.
Therefore, it is desirable to provide fabric softening compositions which are stabilised by nonionic stabilisers but which maintain, or even increase their softening performance in the presence of such compounds.
FR 2540901 discloses a composition for conditioning textiles comprising a cationic softening compound and optionally fluid oils, e.g. Vaseline (RTM) oil.
EP-A1-0059502 discloses dilute softening compositions comprising 0.5 to 5% of oil and 0.1 to 2% of an ammonium surfactant having an alkoxylation number of from 1 to 9.
GB 1601360 discloses a softening composition comprising a cationic fabric softener and a C10-40 hydrocarbon, and teaches that the hydrocarbon is a cheaper replacement for nonionic materials previously proposed for use with the cationic fabric softener.
EP-A1-0079746 discloses a concentrate comprising a cationic fabric softener, a C10-40 hydrocarbon and an organic solvent.
EP-A1-0032267 discloses a softening composition comprising a cationic softener, a C12-40 hydrocarbon and an amine derivative compound.
EP-A1-0569847 relates to nitrogen free softening agents containing alkoxylated fats or oils. There is no disclosure of either the nonionic alkoxylates or the level of alkoxylation specified in the present invention.
WO-A1-96/14375 relates to compositions for the aftertreatment of washed laundry comprising 0.1 to 30 wt % of a water insoluble quaternary ammonium compound, 0.1 to 50 wt % of a water soluble quaternary ammonium compound, 0 to 5 wt % of a terpene or terpene-containing compound, 0.1 to 20 wt % of an acid and 0.1 to 20 wt % of an emulsifier. The compositions are in the form of dispersions or clear solubilizates.
None of these documents solves the problem of providing a stabilised fabric softening composition which delivers maintained or improved softening performance.
A further problem associated with conventional concentrated fabric softening compositions is that the perfume intensity on fabric treated with the fabric softening composition decreases significantly during storage of the fabric. However, perfume intensity upon storage of treated fabric is desired by consumers.
Therefore, it is desirable to provide a fabric softening composition which provides fabrics with a more intense perfume upon storage of the fabrics.